Hi folks,
Hope this isn't all old news, but after Bill Gunston's 'Back to Balloons and Gliders?' ('Air International', May 1986, Vol. 30, No. 5, pp. 228-9), here are references to (alleged) early 'stealths' (reduced optical/radar signature):
1) Professor S. G. Kozlov's 'Nyevidimyi Samolyet'...